1. Field of the Invention.
This invention relates to trailer hitches for hitching trailer vehicles to tractor vehicles, and more particularly relates to trailer hitch apparatus that may be universally applicable to any tractor vehicle equipped to tow a trailing vehicle, such as a trailer.
2. Description of the Prior Art.
The prior art relating to this invention is believed to be contained in Class 280, sub-classes 415A; 415R; 474; 477; 491A; 491E; 500; 501; 511; 514; and 515.
As a result of a search in the area indicated, the following United States patents were found and examined in connection with the preparation of this application: U.S. Pat. Nos. 2,570,933; 2,838,327; 2,871,030; 2,872,213; 3,271,050; 4,239,253; 4,248,450; 4,280,713; 4,546,994.
Referring to each of the patents above in the order in which they were issued, U.S. Pat. No. 2,570,933 is directed to a trailer hitch assembly formed in two sections, one of the sections constituting a permanently attached section that remains always attached to the underside of the vehicle and out of sight so as not to detract from the appearance of the vehicle, while a second section constitutes a detachable section adapted to be removably attached to the first permanently attached section.
U.S. Pat. No. 2,838,327 embodies a cylindrical receptacle within which is detachably secured by a pin the connector tube on which is mounted the trailer hitch ball. As illustrated in FIG. 5 of this patent, the connector tube may be rotated through 90 degrees to place the ball in a lower position and projecting to one side so as to leave the license plate numbers of the towing vehicle exposed. There is no suggestion in this patent of an auxiliary connector socket on the main connector tube to receive a complimentarily configured plug on which a ball may mounted.
U.S. Pat. No. 2,871,030 is also directed to a trailer hitch assembly, and particularly to one which provides a flexible connection between the trailer and the tractor, allowing angling around three mutually perpendicular axis.
U.S. Pat. No. 2,872,213 is directed to a trailer hitch assembly that facilitates the permanent attachment of two balls of different sizes to the trailer hitch assembly. In this structure, the ball support plate is bored to receive the shanks of two different balls, the shanks being axially aligned but projecting from opposite sides of the plate. The plate is provided with flanges that permit 180 degree pivotal repositioning of the ball support plate and detachable attachment thereof to an appropriate support bracket mounted on the tractor vehicle.
U.S. Pat. No. 3,271,050 is directed to a trailer hitch assembly in which the conventional connector tube with the ball thereon is removed and replaced by an auxiliary connector tube on which is rotatably mounted a hardened steel wheel for the purpose of protecting the trailer hitch receptacle tube when the vehicle, without the trailer attached, passes over dips or depressions in the roadway, which might bring the receptacle tube into contact with the pavement.
U.S. Pat. No. 4,239,253 relates to a structure categorized as a body extender, and includes a pivotal connection between two parallel frame members that permit pivotal movement of the trailer about a horizontal axis, but do not appear to permit pivotal action of the trailing vehicle about a vertical axis.
U.S. Pat. No. 4,248,450 discloses a structure for mounting a multiplicity of trailer hitch balls on a tractor vehicle. The balls, extending in four different directions, are mounted on a square tube that is rotatably mounted on a heavy cylindrical pin permanently connected to the tractor vehicle. The square tube is rotatably mounted on the heavy pin, and a removable lock pin is provided to prevent relative rotation of the ball mounting square tube in relation to the heavy pin when a particular ball has been selected for use.
U.S. Pat. No. 4,280,713 is directed to a trailer hitch assembly in which the conventional receptacle tube which is permanently attached to the vehicle is adapted to releasably receive either a straight connector tube as illustrated in FIGS. 5 and 6 and on which a ball may be mounted, or a vertical offset connector tube 28 having upper and lower tube extensions 32 and 34. The upper tube extension is releasably secured in the receptacle by a pin. The lower tube extension is utilized to releasably mount the square body member or tube 42 by means of a pin, and on which the balls 54 of different sizes may be mounted.
U.S. Pat. No. 4,546,994 relates to the type of trailer hitch assembly commonly known as a "fifth wheel" in which the hitch ball is mounted within the bed of a pickup truck. In this construction, the receptacle tube is square and its axis is vertical instead of horizontal. The upper end of the receptacle tube is welded to a plate that is bolted to the bed of the pickup truck and to the framework underneath the bed. The trailer hitch ball is mounted on a plate which is in turn welded permanently to the upper end of the connector tube, which is square in cross-section and dimensioned to pass snugly through the plate and into the square vertical receptacle tube. The connector tube with ball attached is releasably held by an appropriate pin.
It is one of the object of the present invention to provide a trailing vehicle, such as a trailer, with a tongue assembly, including a trailer hitch portion that is permanently attached to the trailing vehicle tongue and which may be universally attached for pivotal movement to any tractor vehicle equipped with a conventional rectangular or square receptacle tube.
Another object of the invention is the provision of an adaptor constituting a connector tube adapted to be releasably attached to the conventional receptacle tube permanently attached below a tractor vehicle, and which will universally interface and cooperate with the trailer hitch ball permanently and pivotally attached to the trailing vehicle tongue.
Still another object of this invention is the provision of a tailer hitch ball permanently mounted on a plug member adapted to slidably engage a socket, and between which means are provided for releasably locking the plug in the receptacle socket.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiments illustrated and described, since it may be embodied in various forms within the scope of the appended claims.